Akiko Yosano is a member and personal physician of the Armed Detective Agency. Her ability is a rare healing ability, Thou Shalt Not Die. Yosano is a young woman who takes care of her appearance. She has straight, dark hair cut into a bob that reaches past her chin and bangs. Her eyes are magenta. She wears a white button-up blouse with puffy sleeves that end in the middle of her forearm. Her shirt is tucked into a plain black skirt that flares out above the knee. She wears gloves that reach past her wrist, a black tie, and black tights. Yosano wears red high heels and a golden butterfly hairpin on the left side of her head. When she served as a student surgeon for the military during the Great War, she wore an apron over her military clothes. After the war, Yosano has been isolated and wore a white hospital gown. When she examined Kyōka in the agency's infirmary, she wears a white coat. Yosano wears a simple blouse and skirt with a doctor's coat and glasses when she was transported into Poe's novel. After the cannibalism, Yosano wears a more formal attire during the agency's celebration. After the Armed Detective Agency is framed as terrorists, she suddenly wears a white hood suit and changes into a riot gear with black boots and black gloves, originally belonging to the military police. After being captured by the Hunting Dogs, she wears a prison uniform. Yosano carries herself with grace and dignity. She prides herself on being both a strong woman and a capable doctor, which is why she does not take too kindly to those who belittle her in both respects. She is a feminist who believes that now is the age of equal rights for men and women. She is almost always depicted as calm and composed, but when angered she is quite the force to contend with, often sadistic in her retaliation. She's also prone to prominent sadistic and aggressive tendencies, which are amplified by her ability's conditions. As a result, most members from the Agency flee when in her presence; Jun'ichirō Tanizaki specifically advised the newcomer Atsushi Nakajima to avoid getting injured even in the slightest to avoid experiencing her unique brand of "treatment". Even the members who entered the Agency around the same generation as her, including Ranpo Edogawa and Doppo Kunikida, recoil from the thought of getting "treated" by Yosano. Moreover, she has a penchant for the morbid and the gruesome, notably gleefully taking apart her patients and healing them with her ability afterwards. She also takes interest in reading the obituaries and in a news article once that reported a fire incident, with which she remarked how it must have "smelled wonderful". When the Agency was dispatched to Standard Island for a mission, Yosano brought with her aboard the ship some photos of corpses from various crime scenes and reveled at the sight of each photo. In the Agency, Yosano is typically nonchalant albeit quite perceptive during briefings and missions, occasionally commenting during meetings with her collected and relaxed demeanor regardless how grisly or serious the situation is. For instance, when they briefed on the Azure Apostle's letters-cum-forewarnings, Yosano casually remarked how when they briefed on the serial suicides of ability users overseas, Yosano calmly perceived that there was more to their case meeting than just having to make them take extra precaution. As the sole doctor of the Agency, she highly values human life and is significantly averse to meaningless deaths and killings. She would violently admonish those who believe otherwise and is very keen on doing so without much hesitation, especially Motojirō Kajii who openly expressed his curiosity towards death through his "experiments" that involved civilians into his bombings. Moreover, aside from being the Agency's physician, Yosano is regarded with high respect among her peers for her vast experience. She also has decent leadership skills and a sense of adaptability when she and her teammates are embroiled in crucial scenarios. During the hunt for the Agency by the Hunting Dogs, Yosano took initiative with instructing Tanizaki and Kenji Miyazawa that they escape separately, so as to increase their chances of survival. She also later directed Atsushi and Kyōka Izumi to get their hope to reviving the Agency, which involved healing Margaret Mitchell, into safety. On casual days, Yosano has a fondness for shopping to a great extent and would invite her other co-workers to accompany her. She would often buy large amounts of clothes and other products and force other agents to carry them for her; she also once subtly threatened Atsushi not to drop her purchases, much to the then rookie's alarm. Moreover, she seems to have a high tolerance to alcohol and even invited Kunikida to drink with her during Kyōka's entrance party, telling him that the others were "no fun to drink with".